1. Field of the Invention
The present invention relates to a housing case for an electronic circuit board, more particularly to a housing case that houses an electronic circuit board in a space formed by a case body and cover.
2. Description of the Related Art
Since a housing case for an electronic circuit board is generally used in an environment where water and oil components may fly and adhere thereto or a dusty environment, it is necessary to enhance waterproof and dust resistance properties by hermetically sealing a space for housing the board. There is widely known a technique to bond a case body and cover using adhesive so as to seal the space.
An amount of adhesive used for bonding the case body and cover varies depending on an environment of the housing case, a type of adhesive or the like. Specifically, when the housing case is installed in an environment where relatively many water components fly, adhesive should be increased to enhance waterproof property, while, in the case of relatively few flying water components, a small amount of adhesive suffices.
Therefore, it is preferable that a housing case for an electronic circuit board is configured to be able to change an amount of adhesive in accordance with the environment for enhancing waterproof property, etc. In the technique taught in Japanese Laid-Open Patent Application No. 2003-258451, a housing case is installed with a base supporting a board and the height of the base is set in accordance with the environment, so that a gap applied or provided with adhesive (a gap for sealing) can be variable, thereby changing an amount of the adhesive.
However, in the reference, since the height of the base, i.e., the amount of the adhesive (precisely, a gap for sealing) is adjustable only within the height of the board, it may not satisfy a demand to further enhance waterproof property by using a relatively great amount of adhesive. Also, when the height of the base is adjusted, it causes the need to adjust the height of a positioning pin used to determine a position of the board, resulting in complex in the structure.